今天的节目由Alison Gopnik主持。这是艾莉森第二次参加哲学讲座。中国伊朗亚洲杯比赛直播Check out the show she did with us onNature vs. Nurture. Since it's been awhile since I've done a pre-show blog, I thought I'd jot down a few initial thoughts before we take to the air.

首先,思想。想象力是一件很酷的事情，但在某些方面也令人费解。一方面，它有时似乎让我们认识到真正的可能性。来自阿肯色州霍普市的一个孩子幻想长大后成为美国总统。你瞧，这孩子长大后当上了总统。所以有些我们仅仅想象的事情是真的可能发生的。想象力告诉我们它们是可能的，这是有争议的。

另一方面，我可以想象我能够凭自己的自然力量飞行，或者想象我能够以超过光速的速度旅行。但这些事情是不可能的，至少在物理上是不可能的。

If even the impossible is imagineable maybe the imagination doesn't really have any intrinsic power to acquaint us with possibilities after all.

I doubt that's quite right, though. Take my being able to fly by my own natural powers, unaided by motors or wings. That is physically impossible. But maybe it's logically possible. Maybe when I'm imagining that what I'm gaining acquaintance with is a merely logical possibility.

Can we imagine things that are not even logically possible? Maybe, but I don't think we can imagine them very thickly or richly. But that may not say much about the limits of our imagination. Maybe there just isn't anything very much to imagining a logical impossibility. Or maybe in a way there's too much to imagining a logical impossibility. After all, in a logically impossible world literally everything goes. So there's nothing specific, as it were, to this or that logically impossible situation which would distinguish it from any other in our imagination.

Or look at the imagination from another side. Sometimes our imaginations are too constrained by the actual. In that case, the thing we need to do is to unleash the power of the imagination, to let it roam more freely. Remember Condi Rice saying that no one imagined that a group of terrorists might hijack an airplane and use it as a missle. Turns out she probably wasn't speaking the whole truth. But let's forget that for now. It certainly seems as though the folks in charge should really let their imaginations run wild. And if they fail to imagine things that might well happen -- especially if some of those possibilites do turn out to be actual -- we can justly criticize them for a failure of the imagination. Failures of imagination wouldn't be worthy of criticizing, I think, if we didn't think that through imagination we were getting at something real -- a real possibility.

Of course, maybe sometimes we imagine sort of idly, without any deeper cognitive purpose except to engage the imagination. We just kind of play with the imagination. I think kids do a lot of imaginative play, for example. But I don' t think it's at all cognitively idle. I think they are exploring the outlines of the moral universe, figuring out who and what they shall be, gaining acquaintance with a world of possibilities, some near to actual, some quite remote from the actual, gaining fuller acquaintance with the causal and counterfactual structure of the world. All really cognitively momentous stuff.

Philosophy is often an exercise in imagining. A characteristic sort of philosophical question is "how possibly" question. How possibly could a mind embued with rationality, intentionality, consciousness, will, and personhood be just a part of material nature? How possibly could free will subsist in a deterministic universe? How possibly could norms be determined by the facts alone?

To answer such questions, philosophers try to construct in imagination more or less richly characterized alternative possible worlds. And then they try to convince you that the constructed possible world is really not so terribly distant from our own. Or if they want to show that it is not possibly so -- not possible to locate mind in nature or to reconcile free will and determinism, for example -- then they try to show that there is no possible world plausibly like our own in which, say, the mind is just a material thing or free will and determinism co-exist. That too usually involves trying to gain fuller imaginative acquaintance with the totality of possible worlds. Search all the possible worlds in your imagination, you won't find one in which free will and determinism co-exist (except perhaps very remote worlds utterly unlike our own.).

Either way, the point is to try to gain fuller imaginative acquaintance with some set of possibilities and thereby to answer the how possibly question, whatever it was, with which we started.

This post is just to get the juices flowing for the show. I'm sure that after Allison and John enlighten me, I'll have many more thoughts.

Tchau。